Apparatus for the electric transmission of signs



E. EHRHARDT July 20, 1926.

APPARATUS FOR THE ELECTRIC TRANSMISSION OF SIGNS 2 Sheets-Sheet 1 Filed August 5, 1924 July 20 1926.

E. EHRHARDT APPARATUS FOR THE ELECTRIC TRANSMISSION OF SIGNS Filed August 5, 1924 2 Sheets-Sheet 2 Patented July 20, 1926a UNITED STATES PATENT oFr-acs.

ERWIN EHRHRDT, OF HERMSDORF,

NEAR BERLIN,

GERMANY, A. CORPORATION OF GERMANY.

APPARATU FOR THE ELECTRIC TRANSMISSION OF SIGNS.

Application filed August 5, 1924, Serial No. 730,210, and in Germany August 8, 1923.

My invention relates to improvements in apparatus for the electric transmission of signs and is particularly suitable for typeprinting telegraphs in which the imprint of the type at the receiver is effected by a type wheel rotating synchronously with the moving parts of the transmitter." In carrying out my invention the transmission systems known. for the purpose are made use of and my invention consists essentially in the feature that by means of an electro-magnetic coupling rendered operative by the giving of a sign at the transmitter the moving parts of the transmitter and the receiver are each coupled with continuously rotating driving shafts and are each arrested by a locking device when the starting position is reached, which locking device is rendered inoperative simultaneously with the switching in of the coupling magnets and operative with the cutting out of said magnet, the reproduction of the sign transmitted and more particularly the imprint of the type taking place instantaneously at the moving part ofthe receiver when the angular position of the type-wheel corresponding with the sign tobe printed has been reached.

In the drawings aflixed to this specification and forming part thereof two embodiments of my invention are illustrated by way of example.

In the drawing Fig. 1 is a sectional side-elevation of the transmitter of i a type-printing telegraph with mechanical locking device,

Fig. 2 is a section along line II of Fig. 1. and shows the distributing disc in front elevation,

Fig. 3 shows the locking disc in the released position,

Fig. 4 shows the receiverof this telegraph system in side elevation,

Fig. 5 is a section along line II-II of Fig. 4.,

Fig. 6 is a sectional side-elevation of the transmitter of a type-printing telegraph with an electro-magnet locking device,

Fig. 7 is a section along llI16(III1-III of Fig. 6,

Fig. 8 shows the receiver of this system in side el vation-and Fig; 9 is a section along line IV-IV of Fig, 8.

Similar parts are indicated by similar letters or numbers of reference throughout all' the figures of the drawmgs.

Referring to Figs 1 to 3, M is the driving motor which during the operation of the system continuously rotates the driving shaft 1. pon said driving shaft is mounted a pot-shaped magnet 2 which receives its exciting current by means of sliding brushes 3. The shaft 5 to be driven is journaled in bearings 4 and at its front end is mounted an iron coupling disc 6' in such a manner that it firmly adheres'to the potshaped magnet 2 when said magnet is excited. This disc 6 may either be adapted to slide upon the shaft 5 axially while rotating with it or the entire shaft with the fixed half-coupling may have slight axial play in its bearings in order to enable the coupling operations to take place. Upon the shaft 5 is mounted a disc 8, also shown in side-elevation in Figs. 2 and 3. Said disc is provided with a recess or notch 9 which in the initial position of the transmitter is engaged by a lever 10 with a nose or projection 11. The lever 10 is fulcrumed in a bearing or standard 7 and is controlled by a spring 12 having the tendency to force it against the disc 8. The lever forms the armature of a magnet 13 and carries an insulated contact 14 which when the lever 10 is attracted by its magnets cooperates with a back contact 15. The contacts 14 and 15 also remain closed as long as the nose 11 of the lever 10 rests upon the circumference of the disc 8.

Upon the rear end. of the shaft 5 is mounted a brush arm 17' which rotates above a distribution disc 18; The brush is connected with one conductor L, of the telegraph line by means of a slip-ring. The other conductor L of this line contains the line or main battery BL and is connected with one contact segment 20 of the distributing disc 18. With the other segments 21, 22, 23, 2 1' of the disc are connected the keys 26, 27, 28, 29." In thestarting position of the apparatus the brush arm 17 is upon an insulated disc 30.

NEAR BERLIN, GERMANY, Assrenoa 'ro- I srnmnns a nansxn, AKTIENGESELLSCHAFT, or srnmnnssranr,

For the sake of simplifying the illustrations four type keys 26 to 29 only are illustrated. Their number as well as the number of the corresponding segments 21 to 24 upon the distributing disc 18 corresponds in the actual construction of the apparatus with all the letters of the alphabet and signs. The key board is also only diagrammatically illustrated in other respects as it is perfectly well known and is only described with a view of more easily explaining the complete type transmitting system. To the various keys belong contacts 30,31, 32 and 33'which are closed when the keys are depressed. All the keys control a contact rail 35 which during the depression of any key moves a lever 36 change over the contacts 37 and 38.

The manner of operation of this system is as follows:

The motor M continuously drives the potshaped coupling magnet 2. When a keyis depressed, for instance the key 26, the lever' 36 is changed over and its tail and moves from the contract 37 to the contact 38. The release magnet 13 now receives the discharge current rush of a condenser 40 which in the position of rest of the lever 36, was charged by the local battery l3 by way of the contact 37. The magnet 13 attracts the lever 10 so that on the one handthe nose 11 is withdrawn from the notch of the locking disc 8 and on the other hand the contacts 14, 15 are closed. The shaft 5 is thus released and the pot-shaped magnet 2 receives exciting current from the battery B.. This current is in the first moment the charging current of a condenser the exciter circuit of the coupling magnet 2 is interrupted and the shaft 5 is arrested. The condenser 41 then discharges across its resistance 42 connected in parallel with it.

During the rotation of the shaft 5 the brush arm 17 has first-passed from the insulating segment 30 to the segment 20 and a current surge is sent from the line battery BL across the two line conductors L L by way of the segment 20 and the slipring 19 which efiects the release of the receiver. A further surge or rush of current takes place as soon as the brush arm 17 sweeps the segment 21 connected with the depressed key 26 which surge eifects the reproduction of the corresponding letter or sign.

Referring to Figs.4 and" 5, it will be seen that the receiver consists essentially of a device or mechanism very similar to the trans- 50 insulated upon it.

The manner of operation of the receiver is the following: during the first current rush in the line L L passing over the segment 20 of the transmitter the line relay LR is excited for a short period and by attracting its contact lever 51 opens the contact 52 and closes the contact 33. In correspondence herewith the condenser 40 which had been charged from the battery B while the contact 52 was closed now discharges over the distributing switch 17, the segment 50 and the releaser magnet 13. This magnetreleases the shaft 5 exactly as in the case of the transmitter and closes the contacts 14 and 15 so that the coupling magnet 2 receives current and couples the shaft 5 with the motor shaft 1. The brush arm 17 then passes on to the distributing ring 49 connected with the printing magnet 45 and in the moment in which the second sign surge of the transmitter takes place (in the case mentioned across the segment 21), the line relay LR is again excited and the discharge current rush of the condenser 40 passes across the lever 51, contact 53, brush arm 17 ring 45. The latter knocks the hammer 45 against the paper tape 44 and the type wheel 43 so that the sign given at the transmitter is imprinted on the tape. After a complete revolution of the'shaft 5 said shaft is arrested at the locking disc 8 by means of the locking lever 10, 11 in exactly the same manner as at the transmitter.

vReferring to Fig. 6 which shows a typeprinting telegraph apparatus in sectional side-elevation in which the locking or arrest ing mechanism is operated electro-magnetically and Fig. 7 which is a transverse section along the line TIL-III of Fig. 6 and shows the distributing disc in front elevation, M is again the motor which continu-- ously drives the shaft 1 on which the potshaped coupling magnet 2 is mounted, The armature disc 55 mounted on the shaft 5 is effected on the one hand by the coupling magnet 2 and on the other hand by the stationary brake magnet 56. The disc armature 55 is again adapted to slide axially upon the shaft 5 or the shaft 5 is axially movable to such an extent that the armature 55 can come in contact either with the pot shaped magnet 8 or the brake magnet 56. Upon the shaft 5 are mounted brush arms a ass 57 which carry insulated brushes 58, 59 of whichv the brush 58-is connected by means of a sliding brush 60 with one pole of the local battery B and the brush 59 by means of a sliding brush 61 with one branch L, of the line. two concentric contact rings. The outer comprises a contact segment 62 in the initial position of the brush and an annular contact 63 connected with the terminal of the coupling. magnet 2. The inner contact ring comprises a release contact segment next to the insulated initial position of the corresponding contact brush 58. "Its further sign contacts 21 to 24 are connected with the printing keys 26 to 29 the con struction of which corresponds with that operative position of'the 38 through the coils of shown in Figs. 1 and 2. A modification as compared with the first example consists in the feature that instead of the release ma net a change-over magnet is provided here across the'contacts 66 or 67 of which either the coupling magnet 2 or the brake magnet 56 is excited.

The manner of operation of the transmitting mechanism is the following: in the inoperative position the brake magnet 56 r'eceives current from the battery B sliding brush 60, contact brush 59, segment 62', back contact 67 of the magnet 65 and a resistance 69 connected in parallel with the condenser 68. As soon as a key, for instance the key 28 is'depressed the key rail 35 changes the key lever 36 over against the contact 38 so that the discharge current rush of the con denser 40, which had been charged in the inthe contact 37, flows by way of the contact a magnet 65. This magnet sharply attracts its armature 70 and thus interrupts the exciter circuit 'of the.

brake magnet 56 at the contact 67. Simultaneously it closes -at the contact 66 the circuit of the coupling magnet 2 which includes the distributing brush 59, the back contact segment 62, armature 70, contact 66, excite;- coil 2, condenser 41 and the battery B so that first a strong charging current surge is produced at the condenser which is later on followed by a weaker holding current across the resistance 42. The shaft 5 rotates and the contact brush 59 passes on to the ring contact 63 so that the holding circuitfor the coupling magnet remains closed. The brush 58 first passes on to the release segment 20 so that a current surge takes place from the line battery BL acrossthe line conductors L L as in the first described example. Later on a current surge is despatched for imprinting the sign across the contact segment 23 in the manner already described, for instance by depressing thekey 28. When the shaft 5 has completed a revolution the brush arm 59 passes over the'inuulation on to the The distributing disc 18 contains mechanism across,

segment 62- whereby the.

holding circuit for the coupling magnet 2 is interrupted and on. the other hand the brake magnet 56 is again made operative which arrests the driven parts in the initial position.

- The receiver cooperating with the just described transmitter is illustrated in the Figures 8 and 9. Referring to'these figures the I type wheel 43 is mounted on the shaft 5 simi- Tlar to the mechanism illustrated in Fig. 4.

This type wheel cooperates with the hammer 46 actuated by the printing magnet 45. The distributor 71 is shown in front elevation in Fig. 9 which is a cross section along the line IV-IV of Fig. 8. It consists of two ring contacts 72, 73 the former of which is pro- .vided with an insulating segment 75 in the starting position while the latter ring 73 1s furnished with a conducting part 74 for this position. nected with each other and by means of a sliding brush 78 with the local battery B This circuit is controlled by the line relay LR the armature 80 of which operates two pairs of contacts 81, 82 and '83, 84.

e manner of operation of this mecha-' 50 that the condenser is charged by the battery B As soon" as the release current surge passes across the lines L L and the line relay attracts its armature 80 a changing over from the contact 83 to the contact 84 takes place and the coupling magnet 2 receives the charging current surge of the condenser .41 across the contacts 84 and the segment 74. Simultaneously the brake magnet 55is cut out so that the receiver shaft 5 begins to revolve. The brush 77 then passes on to the ring contact 73 and the holding circuit of the coupling resistance 42 is closed. The changing over at the contacts 81, 82 taking place simultaneously with the first excitation of the line relay has no effect because the brush 72 controlling the printing magnet 45 still stands on the insulation 75. On arrival of the sign giving current surge the line relay LR is excited again. Now the discharge current surge of the condenser 40 passes over the contact 82, the printing magnet 45, the ring contact 72 and the brushes 76 and 78 so that the imprint of the type or the like takes place at the right moment. The changing over at the relay contacts 83, 84 taking place during the printing current surge remains without effect. Only when the contact brushes 75, 77 reach'the initial position the The two brushes 76, 77 are conmagnet 2 across the exciter circuit of the coupling magnet 2 is interrupted and the circuit of the brake magnet 56 closed so that the moving parts come to rest again in the initial position.

It will be readily understood that I do not limit myself to the exact details of construction of the mechanisms illustrated by Way of example and that these may be modified within the ambit of my claims Without departing from the spirit of my invention.

What I claim as my invention and desire to secure by Letters Patent is 1. In apparatus for the electric transmis- S1011 of signs in combination, continuously revolving driving shafts at the transmitter and at the receiver station, mechanism for transmitting signs at the transmitter station, mechanism for receiving and reproducing said signs at the receiver station and an electro-magnetic coupling for connecting sa d transmitting and receiving mechanisms w1th said continuously revolving shafts, and means for releasing said coupling after a complete revolution.

2. In apparatus'for the electric transmiss1on of signs in combination, continuously revolvlng driving shafts at the transmitter and at the receiver station, mechanism for transmitting signs at the transmitter station, mechamsm for receiving and reproducing said slgns at the receiver station, an electromagnetic coupling for connecting said transmitt-mg and receiving mechanisms with said continuously revolving shafts, and means for automatically releasing said coupling after a complete revolution of said transmitting and receiving mechanisms.

3. In apparatus for the electric transmis- $1011 of signs in combination, continuously revolving driving shafts at the transmitter and receiver stations, shafts adapted to be drlven by said drivinsgl shafts, locking discs upon said driven afts provided with notches, locking levers adapted to engage said notches, release magnets adapted to control said levers, electro-magnetic couplings adapted to connect said driving shafts with said driven shafts, said locking levers being adapted to keep the exciter circuit of said coupling closed when sliding upon the circumference of said locking disc and to open at when engagingthe notch in said locking 4. In apparatus for the electric transmisslon of signs in combination, continuously revolvin driving shafts at the transmitter and at t e receiver stations, mechanism for transmitting signs at the transmitter station comprising a driven shaft, mechanism for receiving and reproducing said signs at the receiving station comprising a driven shaft, an electro-magnetic coupling for connecting said transmitting and said receiving mechanism with said continuously revolving shafts, a brake magnet mounted upon said driven shaft at the transmitter and receiver station anda change-over magnet at each of said stations adapted to lead the exciter current either over said brake magnet or said coupling magnet.

5. In apparatus for the electric transmission of signs in combination, continuously revolving driving shafts at the transmitter and at the receiver station, mechanism for transmitting signs at the transmitter station comprising a driven shaft, mechanism for receiving and reproducing said signs at the receiver station comprising a driven shaft, electro-magnetic couplings for connecting said transmitting and said receiving mechanism with said continuously revolving shafts, additional current sources for energizing said couplings, and means for controlling the currents from said sources to increase the intensity of the energizing currents When the/ energizing circuit is first closed and to subsequently decrease the intensity during the remainder of the energization.

6. In apparatus for the electric transmission of signs in combination, continuously revolving driving shafts at the transmitter and at the receiver station, mechanism for transmitting signs at the transmitter station comprising a driven shaft, mechanism for receiving and reproducing said signs at the receiver station comprising a driven shaft, electro-magnetic couplings for connecting said transmitting and said receiving mechanism with said continuously revolving shafts, additional current sources for energizing said couplings, a brake magnet mounted upon said driven shaft at the transmitter and receiver station and a change-over magnet at each of said stations adapted to lead the exciter current either over said brake or said coupling ma net, and means for controlling the current rom said additional sources to increase the intensity of the energizing currents when the energizing circuit is first closed and to subsequently decrease the intensity during the remainder of the energization.

7. In apparatus for the electric transmission of signs in combination, continuously revolvin driving shafts at the transmitter and at t e receiver station, mechanism for transmitting signs at the transmitter station comprising a driven shaft, mechanism for receiving and reproducing said signs at the receiver station comprising a driven shaft, electro-magnetic couplings for connecting said transmitting and said receiving mechanism with said continuously revolving shafts, a. current source and a circuit for each coupling, a condenser in said circuit and a resistance bridging said condenser, the starting excitation ofthe magnets directly controlling the driven parts being effected by the charging current for said condenser and the permanent excitation being the resistance bridging said current for the conducted over condenser.

8. In apparatus for the electric transmission of signs in combination, continuously revolving driving shafts at the transmitter and at the receiver station, mechanism for transmitting signs at the transmitter station comprising a driven shaft, mechanism for receiving and reproducing said signs at the receiving station comprising a driven shaft, electro-magnetic couplings for connecting said transmitting and said receiving mechanism with said continuously revolving shafts,

1 a current source and a circuit for each cou- 

